Montgomery County, one of Maryland's wealthiest jurisdiction, has spent more than $300,000 fighting a lawsuit that argues that the state's system of financing education unconstitutionally discriminates against children living in poorer areas.

Montgomery County Executive Charles Gilchrist said yesterday that if the suit were won by those challenging the state system, it could mean the future loss of "tens of millions of dollars" in state school aid to his county.

The suit, according to lawyers representing Montgomery, seeks a major overhaul in the way the state distributes school aid.The county's lawyers say such a change "would likely be at the expense of Montgomery County's school system and its taxpayers."

Although not named as a defendant in the suit, Montgomery felt its interests so threatened that officials obtained special permission to help the state attorney general's office defend the case. The county hired top lawyers from one of Baltimore's most venerable law firms for the task and is likely to spend far more than $300,000 -- perhaps several hundred thousand more -- before the case is finished.

The suit, set for trial in Baltimore in September, was filed by the city of Baltimore and three of the state's poorest rural counties -- Somerset, St. Mary's and Caroline. It parallels a series of legal challenges elsewhere that have brought about sweeping changes in the way states around the country pay for their local schools.

Lawyers for the four challenging jurisdictions deny that the purpose of the suit is to "reallocate resources from the state's most affluent school districts to the financially distressed districts."

In states where similar suits have brought about "financial reform . . . the have-not districts do receive greater school aid, but not at the expense of the have districts," said Elliott Lichtman, one of the attorneys for Baltimore city and the three rural counties. "Instead of redistributing the existing pie, the pie has gotten larger and the have-nots have received a greater portion of the increase."

The Maryland suit, filed last year in a state court in Baltimore, asserts that because local property taxes are the major source of funding for the state's 24 school systems, students who live in poorer areas inevitably have "lesser and inadequate educational opportunity."

In the past decade, the state has created and poured increasing funds into a complex series of aid formulas designed specifically to narrow the gap between richer and poorer districts. But the suit claims that these efforts have been inadequate.

Despite these efforts to "equalize" the amount each district has to spend to educate each child, the difference remains great: Montgomery County in 1977 spent $2,152 to educate each pupil while rural Caroline County on the Eastern Shore spent $1,415.

The existing system is therefore in violation of federal and state constitutional guarantees of equal protection and also of Maryland's obligation to provide a "thorough and efficient system of free public schools," the suit contends.

Lawyers for the state officials who are named as defendants in the case deny the system is unconstitutional and contend that the obligation to provide a "thorough and efficient system" does not "mandate that the General Assembly ensure 'equal educational spending' or 'equal educational opportunity' for all school children" in all the jurisdictions.

Montgomery Executive Gilchrist says the county and its legislative representatives have "strongly supported" the idea of increasing state aid to attempt to equalize school expenditures throughout the state. Indeed, the complex state "equalization" formula bears the name of two Montgomery legislators -- Del. Lucille Maurer and former acting governor Blair Lee III, several officials pointed out.

Montgomery County Council President Scott Fosler saw nothing incongruous about the county's support for equalizing aid and its stance against the lawsuit. "It's reasonable to expect the less wealthy (jurisdictions) to get more state aid than the more wealthy," he said. "But it's a matter of degree. How far do you go? We're trying to assure a reasonable balance is struck."

The county hired Baltimore lawyer Shale Stiller, who played a major role in a landmark school finance case before the U.S. Supreme Court. The county has paid for 5,600 hours of legal work since last year by Stiller, four other lawyers in the firm, and several researchers who charge between $30 and $120 an hour for their services, according to the county attorney's office.

Baltimore School Superintendent John L. Crew said, "I wish Montgomery had not gotten into it. Montgomery is putting an awful lot of resources into helping the state in defense (of the suit) . . . I don't think the state would have had all those resources."

Meanwhile, the city and three rural counties have hired their own high-powered legal talent, including Lichtman, a partner in a prominent Washington civil rights firm, and three lawyers from one of Baltimore's most respected law firms. According to Crew, the effort has cost the city "well over $100,000" at this point.